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Subject[RFC PATCH 5/8] misc: emif: handle frequency and voltage change events
Date
Change SDRAM timings and other settings as necessary
on voltage and frequency changes. We calculate these
register settings based on data from the device data
sheet and inputs such a frequency, voltage state(stable
or ramping), temperature level etc.

Signed-off-by: Aneesh V <aneesh@ti.com>
---
drivers/misc/emif.c | 741 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/emif.h | 97 +++++++
2 files changed, 838 insertions(+), 0 deletions(-)

diff --git a/drivers/misc/emif.c b/drivers/misc/emif.c
index ba1e3f9..36ba6f4 100644
--- a/drivers/misc/emif.c
+++ b/drivers/misc/emif.c
@@ -62,6 +62,527 @@ struct emif_data {
};

static struct emif_data *emif1;
+static u32 t_ck; /* DDR clock period in ps */
+
+/*
+ * Calculate the period of DDR clock from frequency value
+ */
+static void set_ddr_clk_period(u32 freq)
+{
+ /* Divide 10^12 by frequency to get period in ps */
+ t_ck = (u32)DIV_ROUND_UP_ULL(1000000000000ull, freq);
+}
+
+/*
+ * Get the CL from SDRAM_CONFIG register
+ */
+static u32 get_cl(struct emif_data *emif)
+{
+ u32 cl;
+ void __iomem *base = emif->base;
+
+ cl = (readl(base + EMIF_SDRAM_CONFIG) & CL_MASK) >> CL_SHIFT;
+
+ return cl;
+}
+
+static void do_freq_update(void)
+{
+ /* TODO: Add an implementation when DVFS framework is available */
+}
+
+/* Find addressing table entry based on the device's type and density */
+static const struct lpddr2_addressing *get_addressing_table(
+ const struct ddr_device_info *device_info)
+{
+ u32 index, type, density;
+
+ type = device_info->type;
+ density = device_info->density;
+
+ switch (type) {
+ case DDR_TYPE_LPDDR2_S4:
+ index = density - 1;
+ break;
+ case DDR_TYPE_LPDDR2_S2:
+ switch (density) {
+ case DDR_DENSITY_1Gb:
+ case DDR_DENSITY_2Gb:
+ index = density + 3;
+ break;
+ default:
+ index = density - 1;
+ }
+ break;
+ default:
+ return NULL;
+ }
+
+ return &lpddr2_jedec_addressing_table[index];
+}
+
+/*
+ * Find the the right timing table from the array of timing
+ * tables of the device using DDR clock frequency
+ */
+static const struct lpddr2_timings *get_timings_table(struct emif_data *emif,
+ u32 freq)
+{
+ u32 i, min, max, freq_nearest;
+ const struct lpddr2_timings *timings = NULL;
+ const struct lpddr2_timings *timings_arr = emif->plat_data->timings;
+ struct device *dev = emif->dev;
+
+ /* Start with a very high frequency - 1GHz */
+ freq_nearest = 1000000000;
+
+ /*
+ * Find the timings table such that:
+ * 1. the frequency range covers the required frequency(safe) AND
+ * 2. the max_freq is closest to the required frequency(optimal)
+ */
+ for (i = 0; i < emif->plat_data->timings_arr_size; i++) {
+ max = timings_arr[i].max_freq;
+ min = timings_arr[i].min_freq;
+ if ((freq >= min) && (freq <= max) && (max < freq_nearest)) {
+ freq_nearest = max;
+ timings = &timings_arr[i];
+ }
+ }
+
+ if (!timings)
+ dev_err(dev, "Couldn't find timings for - %dHz\n", freq);
+
+ dev_dbg(dev, "timings table: freq %d, speed bin freq %d\n",
+ freq, freq_nearest);
+
+ return timings;
+}
+
+static u32 get_sdram_ref_ctrl_shdw(u32 freq,
+ const struct lpddr2_addressing *addressing)
+{
+ u32 ref_ctrl_shdw = 0, val = 0, freq_khz, t_refi;
+
+ /* Scale down frequency and t_refi to avoid overflow */
+ freq_khz = freq / 1000;
+ t_refi = addressing->tREFI_ns / 100;
+
+ /*
+ * refresh rate to be set is 'tREFI(in us) * freq in MHz
+ * division by 10000 to account for change in units
+ */
+ val = t_refi * freq_khz / 10000;
+ ref_ctrl_shdw |= val << REFRESH_RATE_SHIFT;
+
+ return ref_ctrl_shdw;
+}
+
+static u32 get_sdram_tim_1_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing,
+ u32 ip_rev)
+{
+ u32 tim1 = 0, val = 0;
+
+ val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
+ tim1 |= val << T_WTR_SHIFT;
+
+ if (addressing->num_banks == B8)
+ val = DIV_ROUND_UP(timings->tFAW, t_ck*4);
+ else
+ val = max(min_tck->tRRD, DIV_ROUND_UP(timings->tRRD, t_ck));
+ tim1 |= (val - 1) << T_RRD_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab, t_ck) - 1;
+ tim1 |= val << T_RC_SHIFT;
+
+ val = max(min_tck->tRASmin, DIV_ROUND_UP(timings->tRAS_min, t_ck));
+ tim1 |= (val - 1) << T_RAS_SHIFT;
+
+ val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
+ tim1 |= val << T_WR_SHIFT;
+
+ val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD, t_ck)) - 1;
+ tim1 |= val << T_RCD_SHIFT;
+
+ val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab, t_ck)) - 1;
+ tim1 |= val << T_RP_SHIFT;
+
+ if (ip_rev == EMIF_4D5) {
+ val = DIV_ROUND_UP(timings->tRTW, t_ck) - 1;
+ tim1 |= val << T_RTW_SHIFT;
+ }
+
+ return tim1;
+}
+
+static u32 get_sdram_tim_1_shdw_derated(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing, u32 ip_rev)
+{
+ u32 tim1 = 0, val = 0;
+
+ val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
+ tim1 = val << T_WTR_SHIFT;
+
+ /*
+ * tFAW is approximately 4 times tRRD. So add 1875*4 = 7500ps
+ * to tFAW for de-rating
+ */
+ if (addressing->num_banks == B8) {
+ val = DIV_ROUND_UP(timings->tFAW + 7500, 4 * t_ck) - 1;
+ } else {
+ val = DIV_ROUND_UP(timings->tRRD + 1875, t_ck);
+ val = max(min_tck->tRRD, val) - 1;
+ }
+ tim1 |= val << T_RRD_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab + 1875, t_ck);
+ tim1 |= (val - 1) << T_RC_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + 1875, t_ck);
+ val = max(min_tck->tRASmin, val) - 1;
+ tim1 |= val << T_RAS_SHIFT;
+
+ val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
+ tim1 |= val << T_WR_SHIFT;
+
+ val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD + 1875, t_ck));
+ tim1 |= (val - 1) << T_RCD_SHIFT;
+
+ val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab + 1875, t_ck));
+ tim1 |= (val - 1) << T_RP_SHIFT;
+
+ if (ip_rev == EMIF_4D5) {
+ val = DIV_ROUND_UP(timings->tRTW, t_ck) - 1;
+ tim1 |= val << T_RTW_SHIFT;
+ }
+
+ return tim1;
+}
+
+static u32 get_sdram_tim_2_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing,
+ u32 type, u32 ip_rev)
+{
+ u32 tim2 = 0, val = 0;
+
+ val = min_tck->tCKE - 1;
+ tim2 |= val << T_CKE_SHIFT;
+
+ val = max(min_tck->tRTP, DIV_ROUND_UP(timings->tRTP, t_ck)) - 1;
+ tim2 |= val << T_RTP_SHIFT;
+
+ /* tXSNR = tRFCab_ps + 10 ns(tRFCab_ps for LPDDR2). */
+ val = DIV_ROUND_UP(addressing->tRFCab_ps + 10000, t_ck) - 1;
+ tim2 |= val << T_XSNR_SHIFT;
+
+ /* XSRD same as XSNR for LPDDR2 */
+ tim2 |= val << T_XSRD_SHIFT;
+
+ if (ip_rev == EMIF_4D5) {
+ val = DIV_ROUND_UP(timings->tAONPD, t_ck) - 1;
+ tim2 |= val << T_ODT_SHIFT;
+ }
+
+ val = max(min_tck->tXP, DIV_ROUND_UP(timings->tXP, t_ck)) - 1;
+ tim2 |= val << T_XP_SHIFT;
+
+ return tim2;
+}
+
+static u32 get_sdram_tim_3_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing,
+ u32 type, u32 ip_rev, u32 derated)
+{
+ u32 tim3 = 0, val = 0;
+
+ val = timings->tRAS_max_ns / addressing->tREFI_ns - 1;
+ val = val > 0xF ? 0xF : val;
+ tim3 |= val << T_RAS_MAX_SHIFT;
+
+ val = DIV_ROUND_UP(addressing->tRFCab_ps, t_ck) - 1;
+ tim3 |= val << T_RFC_SHIFT;
+
+ if (ip_rev == EMIF_4D5)
+ val = DIV_ROUND_UP(timings->tDQSCK_max + 1000, t_ck) - 1;
+ else
+ val = DIV_ROUND_UP(timings->tDQSCK_max, t_ck) - 1;
+
+ tim3 |= val << T_TDQSCKMAX_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tZQCS, t_ck) - 1;
+ tim3 |= val << ZQ_ZQCS_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tCKESR, t_ck);
+ val = max(min_tck->tCKESR, val) - 1;
+ tim3 |= val << T_CKESR_SHIFT;
+
+ if (ip_rev == EMIF_4D5) {
+ tim3 |= (EMIF_T_CSTA - 1) << T_CSTA_SHIFT;
+
+ val = DIV_ROUND_UP(EMIF_T_PDLL_UL, 128) - 1;
+ tim3 |= val << T_PDLL_UL_SHIFT;
+ }
+
+ return tim3;
+}
+
+static u32 get_read_idle_ctrl_shdw(u8 volt_ramp)
+{
+ u32 idle = 0, val = 0;
+
+ /*
+ * Maximum value in normal conditions and increased frequency
+ * when voltage is ramping
+ */
+ if (volt_ramp)
+ val = READ_IDLE_INTERVAL_DVFS / t_ck / 64 - 1;
+ else
+ val = 0x1FF;
+
+ /*
+ * READ_IDLE_CTRL register in EMIF4D has same offset and fields
+ * as DLL_CALIB_CTRL in EMIF4D5, so use the same shifts
+ */
+ idle |= val << DLL_CALIB_INTERVAL_SHIFT;
+ idle |= EMIF_READ_IDLE_LEN_VAL << ACK_WAIT_SHIFT;
+
+ return idle;
+}
+
+static u32 get_dll_calib_ctrl_shdw(u8 volt_ramp)
+{
+ u32 calib = 0, val = 0;
+
+ if (volt_ramp == DDR_VOLTAGE_RAMPING)
+ val = DLL_CALIB_INTERVAL_DVFS / t_ck / 16 - 1;
+ else
+ val = 0; /* Disabled when voltage is stable */
+
+ calib |= val << DLL_CALIB_INTERVAL_SHIFT;
+ calib |= DLL_CALIB_ACK_WAIT_VAL << ACK_WAIT_SHIFT;
+
+ return calib;
+}
+
+static u32 get_ddr_phy_ctrl_1_attilaphy_4d(const struct lpddr2_timings *timings,
+ u32 freq, u8 RL)
+{
+ u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY, val = 0;
+
+ val = RL + DIV_ROUND_UP(timings->tDQSCK_max, t_ck) - 1;
+ phy |= val << READ_LATENCY_SHIFT_4D;
+
+ if (freq <= 100000000)
+ val = EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY;
+ else if (freq <= 200000000)
+ val = EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY;
+ else
+ val = EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY;
+
+ phy |= val << DLL_SLAVE_DLY_CTRL_SHIFT_4D;
+
+ return phy;
+}
+
+static u32 get_phy_ctrl_1_intelliphy_4d5(u32 freq, u8 cl)
+{
+ u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY, half_delay;
+
+ /*
+ * DLL operates at 266 MHz. If DDR frequency is near 266 MHz,
+ * half-delay is not needed else set half-delay
+ */
+ if (freq >= 265000000 && freq < 267000000)
+ half_delay = 0;
+ else
+ half_delay = 1;
+
+ phy |= half_delay << DLL_HALF_DELAY_SHIFT_4D5;
+ phy |= ((cl + DIV_ROUND_UP(EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS,
+ t_ck) - 1) << READ_LATENCY_SHIFT_4D5);
+
+ return phy;
+}
+
+static u32 get_ext_phy_ctrl_2_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio | fifo_we_slave_ratio << 11 |
+ fifo_we_slave_ratio << 22;
+}
+
+static u32 get_ext_phy_ctrl_3_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio >> 10 | fifo_we_slave_ratio << 1 |
+ fifo_we_slave_ratio << 12 | fifo_we_slave_ratio << 23;
+}
+
+static u32 get_ext_phy_ctrl_4_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio >> 9 | fifo_we_slave_ratio << 2 |
+ fifo_we_slave_ratio << 13;
+}
+
+static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
+{
+ u32 pwr_mgmt_ctrl = 0, timeout;
+ u32 lpmode = EMIF_LP_MODE_SELF_REFRESH;
+ u32 timeout_perf = EMIF_LP_MODE_TIMEOUT_PERFORMANCE;
+ u32 timeout_pwr = EMIF_LP_MODE_TIMEOUT_POWER;
+ u32 freq_threshold = EMIF_LP_MODE_FREQ_THRESHOLD;
+
+ struct emif_custom_configs *cust_cfgs = emif->plat_data->custom_configs;
+
+ if (cust_cfgs && (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE)) {
+ lpmode = cust_cfgs->lpmode;
+ timeout_perf = cust_cfgs->lpmode_timeout_performance;
+ timeout_pwr = cust_cfgs->lpmode_timeout_power;
+ freq_threshold = cust_cfgs->lpmode_freq_threshold;
+ }
+
+ /* Timeout based on DDR frequency */
+ timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr;
+
+ /* The value to be set in register is "log2(timeout) - 3" */
+ if (timeout < 16) {
+ timeout = 0;
+ } else {
+ timeout = __fls(timeout) - 3;
+ if (timeout & (timeout - 1))
+ timeout++;
+ }
+
+ switch (lpmode) {
+ case EMIF_LP_MODE_CLOCK_STOP:
+ pwr_mgmt_ctrl = (timeout << CS_TIM_SHIFT) |
+ SR_TIM_MASK | PD_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_SELF_REFRESH:
+ pwr_mgmt_ctrl = (timeout << SR_TIM_SHIFT) |
+ CS_TIM_MASK | PD_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_PWR_DN:
+ pwr_mgmt_ctrl = (timeout << PD_TIM_SHIFT) |
+ CS_TIM_MASK | SR_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_DISABLE:
+ default:
+ pwr_mgmt_ctrl = CS_TIM_MASK |
+ PD_TIM_MASK | SR_TIM_MASK;
+ }
+
+ /* No CS_TIM in EMIF_4D5 */
+ if (ip_rev == EMIF_4D5)
+ pwr_mgmt_ctrl &= ~CS_TIM_MASK;
+
+ pwr_mgmt_ctrl |= lpmode << LP_MODE_SHIFT;
+
+ return pwr_mgmt_ctrl;
+}
+
+/*
+ * Program EMIF shadow registers that are not dependent on temperature
+ * or voltage
+ */
+static void setup_registers(struct emif_data *emif, struct emif_regs *regs)
+{
+ void __iomem *base = emif->base;
+
+ writel(regs->sdram_tim2_shdw, base + EMIF_SDRAM_TIMING_2_SHDW);
+ writel(regs->phy_ctrl_1_shdw, base + EMIF_DDR_PHY_CTRL_1_SHDW);
+
+ /* Settings specific for EMIF4D5 */
+ if (emif->plat_data->ip_rev != EMIF_4D5)
+ return;
+ writel(regs->ext_phy_ctrl_2_shdw, base + EMIF_EXT_PHY_CTRL_2_SHDW);
+ writel(regs->ext_phy_ctrl_3_shdw, base + EMIF_EXT_PHY_CTRL_3_SHDW);
+ writel(regs->ext_phy_ctrl_4_shdw, base + EMIF_EXT_PHY_CTRL_4_SHDW);
+}
+
+/*
+ * When voltage ramps dll calibration and forced read idle should
+ * happen more often
+ */
+static void setup_volt_sensitive_regs(struct emif_data *emif,
+ struct emif_regs *regs, u32 volt_state)
+{
+ u32 calib_ctrl;
+ void __iomem *base = emif->base;
+
+ /*
+ * EMIF_READ_IDLE_CTRL in EMIF4D refers to the same register as
+ * EMIF_DLL_CALIB_CTRL in EMIF4D5 and dll_calib_ctrl_shadow_*
+ * is an alias of the respective read_idle_ctrl_shdw_* (members of
+ * a union). So, the below code takes care of both cases
+ */
+ if (volt_state == DDR_VOLTAGE_RAMPING)
+ calib_ctrl = regs->dll_calib_ctrl_shdw_volt_ramp;
+ else
+ calib_ctrl = regs->dll_calib_ctrl_shdw_normal;
+
+ writel(calib_ctrl, base + EMIF_DLL_CALIB_CTRL_SHDW);
+}
+
+/*
+ * setup_temperature_sensitive_regs() - set the timings for temperature
+ * sensitive registers. This happens once at initialisation time based
+ * on the temperature at boot time and subsequently based on the temperature
+ * alert interrupt. Temperature alert can happen when the temperature
+ * increases or drops. So this function can have the effect of either
+ * derating the timings or going back to nominal values.
+ */
+static void setup_temperature_sensitive_regs(struct emif_data *emif,
+ struct emif_regs *regs)
+{
+ u32 tim1, tim3, ref_ctrl, type, irqs;
+ void __iomem *base = emif->base;
+ u32 temperature;
+
+ type = emif->plat_data->device_info->type;
+
+ tim1 = regs->sdram_tim1_shdw;
+ tim3 = regs->sdram_tim3_shdw;
+ ref_ctrl = regs->ref_ctrl_shdw;
+
+ spin_lock_irqsave(&emif->lock, irqs);
+ /* No de-rating for non-lpddr2 devices */
+ if (type != DDR_TYPE_LPDDR2_S2 && type != DDR_TYPE_LPDDR2_S4)
+ goto out;
+
+ temperature_level = emif->temperature_level;
+ if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH) {
+ ref_ctrl = regs->ref_ctrl_shdw_derated;
+ } else if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH_AND_TIMINGS) {
+ tim1 = regs->sdram_tim1_shdw_derated;
+ tim3 = regs->sdram_tim3_shdw_derated;
+ ref_ctrl = regs->ref_ctrl_shdw_derated;
+ }
+
+out:
+ writel(tim1, base + EMIF_SDRAM_TIMING_1_SHDW);
+ writel(tim3, base + EMIF_SDRAM_TIMING_3_SHDW);
+ writel(ref_ctrl, base + EMIF_SDRAM_REFRESH_CTRL_SHDW);
+ spin_unlock_irqrestore(&emif->lock, irqs);
+}

static void __exit cleanup_emif(struct emif_data *emif)
{
@@ -239,6 +760,8 @@ static int __init emif_probe(struct platform_device *pdev)
if (!emif1)
emif1 = emif;

+ emif->addressing = get_addressing_table(emif->plat_data->device_info);
+
/* Save pointers to each other in emif and device structures */
emif->dev = &pdev->dev;
platform_set_drvdata(pdev, emif);
@@ -275,6 +798,224 @@ static int __exit emif_remove(struct platform_device *pdev)
return 0;
}

+static int get_emif_reg_values(struct emif_data *emif, u32 freq,
+ struct emif_regs *regs)
+{
+ u32 cs1_used, ip_rev, phy_type;
+ u32 cl, type;
+ const struct lpddr2_timings *timings;
+ const struct lpddr2_min_tck *min_tck;
+ const struct ddr_device_info *device_info;
+ const struct lpddr2_addressing *addressing;
+ struct emif_data *emif_for_calc;
+ struct device *dev;
+ const struct emif_custom_configs *custom_configs;
+
+ dev = emif->dev;
+ /*
+ * If the devices on this EMIF instance is duplicate of EMIF1,
+ * use EMIF1 details for the calculation
+ */
+ emif_for_calc = emif->duplicate ? emif1 : emif;
+ timings = get_timings_table(emif_for_calc, freq);
+ addressing = emif_for_calc->addressing;
+ if (!timings || !addressing) {
+ dev_err(dev, "not enough data available for %dHz", freq);
+ return -1;
+ }
+
+ device_info = emif_for_calc->plat_data->device_info;
+ type = device_info->type;
+ cs1_used = device_info->cs1_used;
+ ip_rev = emif_for_calc->plat_data->ip_rev;
+ phy_type = emif_for_calc->plat_data->phy_type;
+
+ min_tck = emif_for_calc->plat_data->min_tck;
+ custom_configs = emif_for_calc->plat_data->custom_configs;
+
+ set_ddr_clk_period(freq);
+
+ regs->ref_ctrl_shdw = get_sdram_ref_ctrl_shdw(freq, addressing);
+ regs->sdram_tim1_shdw = get_sdram_tim_1_shdw(timings, min_tck,
+ addressing, ip_rev);
+ regs->sdram_tim2_shdw = get_sdram_tim_2_shdw(timings, min_tck,
+ addressing, type, ip_rev);
+ regs->sdram_tim3_shdw = get_sdram_tim_3_shdw(timings, min_tck,
+ addressing, type, ip_rev, EMIF_NORMAL_TIMINGS);
+
+ cl = get_cl(emif);
+
+ if (phy_type == EMIF_PHY_TYPE_ATTILAPHY && ip_rev == EMIF_4D) {
+ regs->phy_ctrl_1_shdw = get_ddr_phy_ctrl_1_attilaphy_4d(
+ timings, freq, cl);
+ } else if (phy_type == EMIF_PHY_TYPE_INTELLIPHY && ip_rev == EMIF_4D5) {
+ regs->phy_ctrl_1_shdw = get_phy_ctrl_1_intelliphy_4d5(freq, cl);
+ regs->ext_phy_ctrl_2_shdw = get_ext_phy_ctrl_2_intelliphy_4d5();
+ regs->ext_phy_ctrl_3_shdw = get_ext_phy_ctrl_3_intelliphy_4d5();
+ regs->ext_phy_ctrl_4_shdw = get_ext_phy_ctrl_4_intelliphy_4d5();
+ } else {
+ return -1;
+ }
+
+ /* Only timeout values in pwr_mgmt_ctrl_shdw register */
+ regs->pwr_mgmt_ctrl_shdw =
+ get_pwr_mgmt_ctrl(freq, emif_for_calc, ip_rev) &
+ (CS_TIM_MASK | SR_TIM_MASK | PD_TIM_MASK);
+
+ if (ip_rev & EMIF_4D) {
+ regs->read_idle_ctrl_shdw_normal =
+ get_read_idle_ctrl_shdw(DDR_VOLTAGE_STABLE);
+
+ regs->read_idle_ctrl_shdw_volt_ramp =
+ get_read_idle_ctrl_shdw(DDR_VOLTAGE_RAMPING);
+ } else if (ip_rev & EMIF_4D5) {
+ regs->dll_calib_ctrl_shdw_normal =
+ get_dll_calib_ctrl_shdw(DDR_VOLTAGE_STABLE);
+
+ regs->dll_calib_ctrl_shdw_volt_ramp =
+ get_dll_calib_ctrl_shdw(DDR_VOLTAGE_RAMPING);
+ }
+
+ if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4) {
+ regs->ref_ctrl_shdw_derated = get_sdram_ref_ctrl_shdw(freq / 4,
+ addressing);
+
+ regs->sdram_tim3_shdw_derated = get_sdram_tim_3_shdw(timings,
+ min_tck, addressing, type, ip_rev,
+ EMIF_DERATED_TIMINGS);
+
+ regs->sdram_tim1_shdw_derated =
+ get_sdram_tim_1_shdw_derated(timings, min_tck,
+ addressing, ip_rev);
+ }
+
+ regs->freq = freq;
+
+ return 0;
+}
+
+/*
+ * get_regs() - gets the cached emif_regs structure for a given EMIF instance
+ * given frequency(freq):
+ *
+ * As an optimisation, every EMIF instance other than EMIF1 shares the
+ * register cache with EMIF1 if the devices connected on this instance
+ * are same as that on EMIF1(indicated by the duplicate flag)
+ *
+ * If we do not have an entry corresponding to the frequency given, we
+ * allocate a new entry and calculate the values
+ *
+ * Upon finding the right reg dump, save it in curr_regs. It can be
+ * directly used for thermal de-rating and voltage ramping changes.
+ */
+static struct emif_regs *get_regs(struct emif_data *emif, u32 freq)
+{
+ int i;
+ struct emif_regs **regs_cache;
+ struct emif_regs *regs = NULL;
+ struct device *dev;
+
+ dev = emif->dev;
+ if (emif->curr_regs && emif->curr_regs->freq == freq) {
+ dev_dbg(dev, "Using curr_regs - %u Hz", freq);
+ return emif->curr_regs;
+ }
+
+ if (emif->duplicate)
+ regs_cache = emif1->regs_cache;
+ else
+ regs_cache = emif->regs_cache;
+
+ for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++) {
+ if (regs_cache[i]->freq == freq) {
+ regs = regs_cache[i];
+ dev_dbg(dev, "Reg dump found in reg cache for %u Hz\n",
+ freq);
+ break;
+ }
+ }
+
+ /*
+ * If we don't have an entry for this frequency in the cache create one
+ * and calculate the values
+ */
+ if (!regs) {
+ regs = kmalloc(sizeof(struct emif_regs), GFP_ATOMIC);
+ if (!regs)
+ return NULL;
+
+ if (get_emif_reg_values(emif, freq, regs)) {
+ kfree(regs);
+ return NULL;
+ }
+
+ /*
+ * Now look for an un-used entry in the cache and save the
+ * newly created struct. If there are no free entries
+ * over-write the last entry
+ */
+ for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++)
+ ;
+
+ if (i >= EMIF_MAX_NUM_FREQUENCIES) {
+ dev_warn(dev, "regs_cache full - reusing a slot!!\n");
+ i = EMIF_MAX_NUM_FREQUENCIES - 1;
+ kfree(regs_cache[i]);
+ }
+ regs_cache[i] = regs;
+ }
+
+ return regs;
+}
+
+/*
+ * Function un-used right now. Will be used later when DVFS framework
+ * is available
+ */
+static void __attribute__((unused)) do_volt_notify_handling(
+ struct emif_data *emif, u32 volt_state)
+{
+ dev_dbg(emif->dev, "voltage notification : %d", volt_state);
+
+ if (!emif->curr_regs) {
+ dev_err(emif->dev,
+ "Volt-notify before registers are ready: %d\n",
+ volt_state);
+ return;
+ }
+
+ setup_volt_sensitive_regs(emif, emif->curr_regs, volt_state);
+ do_freq_update();
+}
+
+/*
+ * Function un-used right now. Will be used later when DVFS framework
+ * is available
+ */
+static void __attribute__((unused)) do_freq_pre_notify_handling(void *emif_data,
+ u32 new_freq)
+{
+ struct emif_regs *regs;
+ struct emif_data *emif = emif_data;
+
+ regs = get_regs(emif, new_freq);
+ if (!regs)
+ return;
+
+ emif->curr_regs = regs;
+
+ /*
+ * Update the shadow registers:
+ * Temperature and voltage-ramp sensitive settings are also configured
+ * in terms of DDR cycles. So, we need to update them too when there
+ * is a freq change
+ */
+ dev_dbg(emif->dev, "setting up shadow registers for %uHz", new_freq);
+ setup_registers(emif, regs);
+ setup_temperature_sensitive_regs(emif, regs);
+ setup_volt_sensitive_regs(emif, regs, DDR_VOLTAGE_STABLE);
+}
+
static struct platform_driver emif_driver = {
.remove = __exit_p(emif_remove),
.driver = {
diff --git a/include/linux/emif.h b/include/linux/emif.h
index 4ddf20b..347125f 100644
--- a/include/linux/emif.h
+++ b/include/linux/emif.h
@@ -22,6 +22,49 @@
*/
#define EMIF_MAX_NUM_FREQUENCIES 6

+/* State of the core voltage */
+#define DDR_VOLTAGE_STABLE 0
+#define DDR_VOLTAGE_RAMPING 1
+
+/* Defines for timing De-rating */
+#define EMIF_NORMAL_TIMINGS 0
+#define EMIF_DERATED_TIMINGS 1
+
+/* Length of the forced read idle period in terms of cycles */
+#define EMIF_READ_IDLE_LEN_VAL 5
+
+/*
+ * forced read idle interval to be used when voltage
+ * is changed as part of DVFS/DPS - 1ms
+ */
+#define READ_IDLE_INTERVAL_DVFS (1*1000000)
+
+/*
+ * Forced read idle interval to be used when voltage is stable
+ * 50us - or maximum value will do
+ */
+#define READ_IDLE_INTERVAL_NORMAL (50*1000000)
+
+/* DLL calibration interval when voltage is NOT stable - 1us */
+#define DLL_CALIB_INTERVAL_DVFS (1*1000000)
+
+#define DLL_CALIB_ACK_WAIT_VAL 5
+
+/* Interval between ZQCS commands - hw team recommended value */
+#define EMIF_ZQCS_INTERVAL_US (50*1000)
+/* Enable ZQ Calibration on exiting Self-refresh */
+#define ZQ_SFEXITEN_ENABLE 1
+/*
+ * ZQ Calibration simultaneously on both chip-selects:
+ * Needs one calibration resistor per CS
+ */
+#define ZQ_DUALCALEN_DISABLE 0
+#define ZQ_DUALCALEN_ENABLE 1
+
+#define T_ZQCS_DEFAULT_NS 90
+#define T_ZQCL_DEFAULT_NS 360
+#define T_ZQINIT_DEFAULT_NS 1000
+
/* EMIF_PWR_MGMT_CTRL register */
/* Low power modes */
#define EMIF_LP_MODE_DISABLE 0
@@ -29,6 +72,35 @@
#define EMIF_LP_MODE_SELF_REFRESH 2
#define EMIF_LP_MODE_PWR_DN 4

+/* DPD_EN */
+#define DPD_DISABLE 0
+#define DPD_ENABLE 1
+
+/*
+ * Default values for the low-power entry to be used if not provided by user.
+ * OMAP4/5 has a hw bug(i735) due to which this value can not be less than 512
+ * Timeout values are in DDR clock 'cycles' and frequency threshold in Hz
+ */
+#define EMIF_LP_MODE_TIMEOUT_PERFORMANCE 2048
+#define EMIF_LP_MODE_TIMEOUT_POWER 512
+#define EMIF_LP_MODE_FREQ_THRESHOLD 400000000
+
+/* DDR_PHY_CTRL_1 values for EMIF4D - ATTILA PHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY 0x049FF000
+#define EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY 0x41
+#define EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY 0x80
+#define EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY 0xFF
+
+/* DDR_PHY_CTRL_1 values for EMIF4D5 INTELLIPHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY 0x0E084200
+#define EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS 10000
+
+/* TEMP_ALERT_CONFIG - corresponding to temp gradient 5 C/s */
+#define TEMP_ALERT_POLL_INTERVAL_DEFAULT_MS 360
+
+#define EMIF_T_CSTA 3
+#define EMIF_T_PDLL_UL 128
+
/* Hardware capabilities */
#define EMIF_HW_CAPS_LL_INTERFACE 0x00000001

@@ -44,6 +116,31 @@
#define EMIF_CUSTOM_CONFIG_LPMODE 0x00000001
#define EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL 0x00000002

+/* External PHY control registers magic values */
+#define EMIF_EXT_PHY_CTRL_1_VAL 0x04020080
+#define EMIF_EXT_PHY_CTRL_5_VAL 0x04010040
+#define EMIF_EXT_PHY_CTRL_6_VAL 0x01004010
+#define EMIF_EXT_PHY_CTRL_7_VAL 0x00001004
+#define EMIF_EXT_PHY_CTRL_8_VAL 0x04010040
+#define EMIF_EXT_PHY_CTRL_9_VAL 0x01004010
+#define EMIF_EXT_PHY_CTRL_10_VAL 0x00001004
+#define EMIF_EXT_PHY_CTRL_11_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_12_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_13_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_14_VAL 0x80080080
+#define EMIF_EXT_PHY_CTRL_15_VAL 0x00800800
+#define EMIF_EXT_PHY_CTRL_16_VAL 0x08102040
+#define EMIF_EXT_PHY_CTRL_17_VAL 0x00000001
+#define EMIF_EXT_PHY_CTRL_18_VAL 0x540A8150
+#define EMIF_EXT_PHY_CTRL_19_VAL 0xA81502A0
+#define EMIF_EXT_PHY_CTRL_20_VAL 0x002A0540
+#define EMIF_EXT_PHY_CTRL_21_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_22_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_23_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_24_VAL 0x00000077
+
+#define EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS 1200
+
/*
* Structure containing shadow of important registers in EMIF
* The calculation function fills in this structure to be later used for
--
1.7.1


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